The present invention is directed to a method for the production of masks for x-ray lithography which are used to produce a pattern in the x-ray resist material during a reproductin process. Each of the masks consist of a frame having an opening or window, a carrier foil composed of metal which extends across the window, is clamped to the frame and is permeable to x-rays, and a mask structure which is arranged on the carrier foil and is impermeable to x-rays.
X-ray lithography is a reproduction process which uses x-rays to reproduce a structure of an x-ray mask on a substrate by shadow projections. One of the main difficulties in the industrial application of x-ray lithography consists in the production of suitable x-ray masks.
The x-ray mask consists of a frame with a metal foil clamped thereto and of an absorber structure arranged on the metal foil.
In German Pat. No. 26 26 851, a process for the production of masks for x-ray lithography is described. In this process, the structure carrier consists of a metal or synthetic foil which together with the mask structure is formed on a base, for example, glass. The base is then etched away by selective etching using an etching covering in such a manner that only its edge zones remain and forms the outer mask frame having an opening or window.